Biomedical subjects

H Takekawa

Publications and source records attributed to H Takekawa.

At least 19 recordsLinked to original sources

PubMed2001

Organic aerosol formation during the atmospheric degradation of toluene.

Organic aerosol formation during the atmospheric oxidation of toluene was investigated using smog chamber systems. Toluene oxidation was initiated by the UV irradiation of either toluene/air/NOx or toluene/air/CH3ONO/NO mixtures. Aerosol formation was monitored using scanning mobility particle sizers and toluene loss was monitored by in-situ FTIR spectroscopy or GC-FID techniques. The experimental results show that the reaction of OH radicals, NO3 radicals and/or ozone with the first generation products of toluene oxidation are sources of organic aerosol during the atmospheric oxidation of toluene. The aerosol results fall into two groups, aerosol formed in the absence and presence of ozone. An analytical expression for aerosol formation is developed and values are obtained for the yield of the aerosol species. In the absence of ozone the aerosol yield, defined as aerosol formed per unit toluene consumed once a threshold for aerosol formation has been exceeded, is 0.075 +/- 0.004. In the presence of ozone the aerosol yield is 0.108 +/- 0.004. This work provides experimental evidence and a simple theory confirming the formation of aerosol from secondary reactions.

Aerosols↗

PubMed2001

A comparison of middle latency auditory-evoked response in obstructive sleep apnea syndrome before and after treatment.

The ascending reticular activating system seems to be affected by nocturnal hypoxia in obstructive sleep apnea syndrome (OSAS) patients so that their vigilance level is decreased. To evaluate the change in vigilance level in OSAS patients, polysomnography, the Epworth Sleepiness Scale and middle latency auditory-evoked responses (MLR) were measured before and after treatment in seven men with OSAS (mean age 45.4 +/- 12.9 years, mean body mass index 33.3 +/- 7.6 kg/m2). After treatment there was significant improvement of nocturnal hypoxia in OSAS. Peak amplitude of P1 in MLR increased after treatment. There was also improvement of the electrical field distribution of MLR on the scalp. The results suggest that the decreased vigilance level in OSAS patients is reversible with treatment.

Arousal↗

PubMed2001

Amyotrophic lateral sclerosis associated with insomnia and the aggravation of sleep-disordered breathing.

A case of amyotrophic lateral sclerosis (ALS) diagnosed by sleep-disordered breathing is described. The patient's chief complaints were insomnia and nocturnal dyspnea after taking a hypnotic drug. On examination, he showed restrictive ventilatory impairment, alveolar hypoventilation and hypoxia. Polysomnographic examination revealed marked hypoxia during REM sleep periods, decreased duration of REM sleep periods, and increased sleep disruption. Amyotrophic lateral sclerosis was diagnosed by the neurological finding of paraspinal muscle weakness and neurogenic changes revealed by needle electromyography and muscle biopsy. The daytime and nocturnal respiratory insufficiency improved after nasal bilevel positive airway pressure therapy. Amyotrophic lateral sclerosis should be suspected as a cause of insomnia and nocturnal dyspnea.

Amyotrophic Lateral Sclerosis↗

PubMed2001

Parasomnia as an occasion for the diagnosis of Parkinson's disease.

We report a case of Parkinson's disease (PD) diagnosed by REM sleep behavior disorder (RBD). The patient was a 68-year-old man. On admission, rigidity in the left upper and lower extremities, bradykinesia, and gait disturbance were noted. In addition, polysomnography revealed REM sleep without atonia (RWA), and a diagnosis of untreated PD associated with RBD was made. Polysomnographic data showed that REM density decreased and RWA tended to increase after administration of a combination of L-DOPA and DCI (L-DOPA/DCI). Thus, we considered that the pathophysiological mechanism of RBD in this case was based not only on the dysfunction of the brainstem mechanism of RWA, but also on the impairment of dopaminergic neuron.

Aged↗

PubMed2000

[Relapse of idiopathic chylothorax 17 years after remission of congenital chylothorax].

We report a case of chylothorax in a 17-year-old male. As a neonate, had had congenital chylothorax, and was successfully treated with medium-chain triglycerides; but recently presented with dyspnea after an episode of severe coughing. Radiographic examination disclosed abundant effusion in the right chest. The effusion was milky brown, had a creamy supernatant and a high triglyceride level (3085 mg/dl). This condition was diagnosed as idiopathic chylothorax. Lymphangiography showed a rupture of the right thoracic duct. Since the effusion was resistant to conservative therapy, we performed thoracoscopic clipping of the thoracic duct, which reduced the amount of pleural effusion. We speculated that coughing may have caused the rupture of a congenitally weakened thoracic duct.

Adolescent↗

PubMed1999

Technetium-99m-tetrofosmin imaging of lung cancer: relationship with histopathology.

Tc-99m-tetrofosmin is an agent to delineate cancer. To elucidate the usefulness of Tc-99m-tetrofosmin scintigraphy, we analyzed the relationship between the uptake of Tc-99m-tetrofosmin and histopathology in patients with lung cancer. SPECT studies were conducted twice: 15 minutes (early scan), and 60 minutes (delayed scan), after intravenous injection of 740 MBq Tc-99m-tetrofosmin. We calculated the retention index in order to evaluate the degree of Tc-99m-tetrofosmin retention in the primary tumor. The retention indices were significantly lower in squamous cell carcinoma than those of small cell carcinoma or adenocarcinoma. As the retention indices of Tc-99m-tetrofosmin were different in each histopathology, the index might play a part as a tumor marker of lung cancer.

Adenocarcinoma↗

PubMed1998

Intracellular accumulation of thallium as a marker of cisplatin cytotoxicity in nonsmall cell lung carcinoma: an application of inductively coupled plasma mass spectrometry.

BACKGROUND: Thallium-201 (201Tl) scintigraphy has been used to detect malignant pulmonary disease. The mechanism of Tl influx in tumor cells is believed to be similar to that of cisplatin (CDDP) mediated by sodium- and potassium-activated adenosine triphosphatase (Na-K ATPase), and the Na-K ATPase activity may determine the cellular CDDP accumulation and sensitivity to CDDP. The objective of this study was to determine the accumulation of CDDP and Tl in vitro by using inductively coupled plasma mass spectrometry (ICP-MS), a new analytic technique for detecting ultra trace elements, and to evaluate the correlations between cellular CDDP and Tl accumulation, between CDDP 50% inhibitory concentration (IC50) values and cellular CDDP accumulation, and between CDDP IC50 values and cellular Tl accumulation. METHODS: Eight nonsmall cell lung carcinoma (NSCLC) cell lines were used (five adenocarcinomas and three squamous cell carcinomas). The cell lines were exposed to CDDP or Tl for 1 hour, and the resulting cellular accumulation of platinum and Tl was determined by ICP-MS. CDDP IC50 values were determined by a soluble tetrazolium/formazan assay. RESULTS: The authors were able to measure cellular CDDP and Tl accumulation precisely, and heterogeneity in the cellular accumulation of CDDP and Tl existed among the NSCLC cell lines. A significant inverse correlation was observed between CDDP IC50 values and the cellular accumulation of both CDDP and Tl. CONCLUSIONS: ICP-MS is suitable for the determination of cellular CDDP and Tl accumulation in NSCLC cell lines. Cellular Tl accumulation determined by ICP-MS may reflect CDDP cytotoxicity rather than cellular CDDP accumulation.

Adenocarcinoma↗

PubMed1998

Predicting chemotherapeutic response to small-cell lung cancer of platinum compounds by thallium-201 single-photon emission computerized tomography.

Thallium-201 single-photon emission computerized tomography (SPECT) was used to clarify the relationship between 201Tl uptake and the response in chemotherapy to platinum compounds in 21 patients with small-cell lung cancer. 201Tl-SPECT scans were obtained twice: at 15 min (early scan) and 120 min (delayed scan) after an intravenous injection of 111 MBq (3 mCi) of thallium-201 chloride. We obtained the uptake ratio from each scan and calculated the retention index:uptake ratio = region of interest uptake/contralateral normal lung uptake; retention index = (delayed ratio - early ratio)/early ratio. After 201Tl scintigraphy, 12 patients received chemotherapy consisting of platinum compounds and nine were treated with chemoradiation. Among patients receiving only chemotherapy, the retention index correlated with the responses to chemotherapy. In an in vitro study, ouabain, an inhibitor of the Na,K-ATPase pump, reduced sensitivity to cisplatin and inhibited intracellular thallium uptake in the small-cell lung cancer cell line. These studies suggest that 201Tl-SPECT is a useful indicator of response to chemotherapy with platinum compounds in small-cell lung cancer, and that Na,K-ATPase is commonly involved in transporting both thallium and platinum compounds into cancer cells.

Aged↗

PubMed1997

Thallium-201 single photon emission computed tomography as an indicator of prognosis for patients with lung carcinoma.

BACKGROUND: The uptake of thallium-201 (T1-201) in malignant tumors is associated with malignant potential (metastatic potential and proliferative activity). The grade of accumulation of T1-201 in malignant tumors may provide information regarding prognosis. METHODS: A T1-201 single photon emission computed tomography was conducted 120 minutes after intravenous injection of 111 megabecquerel of T1-201 chloride. The authors calculated the uptake ratio to evaluate the degree of T1-201 uptake in the primary tumor. This ratio was compared with survival time and other prognostic factors. RESULTS: The authors studied 152 patients (125 men and 27 women). The group of patients with the low T1-201 uptake ratio survived longer than the group of patients with the high T1-201 uptake ratio (median survival, 58 weeks vs. 33 weeks; P = 0.0138 by the log rank test). The multivariate analysis confirmed that the T1-201 uptake ratio was an independent prognostic factor for survival. CONCLUSIONS: These results suggest that the T1-201 uptake ratio provides independent and objective prognostic information for patients with lung carcinoma.

Adult↗

PubMed1997

Visualization of lung cancer with 99Tcm-tetrofosmin imaging: a comparison with 201T1.

We evaluated the usefulness of 99Tcm-tetrofosmin imaging in lung cancer. The study sample comprised 46 patients with lung cancer. Single photon emission tomography was conducted after the intravenous injection of 740 MBq 99Tcm-tetrofosmin and 111 MBq 201T1-chloride. We obtained an uptake ratio (counts per pixel in the lesion/counts per pixel in contralateral normal lung) for each scan to evaluate the degree of uptake in the tumour. Our results demonstrate that 89.1% of the primary lung cancers were visualized by 99Tcm-tetrofosmin and 95.7% by 201T1. The difference between the 201T1 uptake ratio and the 99Tcm-tetrofosmin uptake ratio was significantly greater in squamous cell carcinomas than small cell carcinomas (P < 0.01) and tended to be greater in squamous cell carcinomas than adenocarcinomas (P = 0.093). This study has indicated that 99Tcm-tetrofosmin, like 201T1, is a highly effective agent in the delineation of lung cancer. The difference between the 99Tcm-tetrofosmin and 201T1 uptake ratios might provide further information regarding the histological type of lung cancer.

Adenocarcinoma↗

PubMed1997

[Mediastinal esophago-bronchogenic cyst presenting as a single mass].

An abnormal shadow was found on a chest X-ray film of a 42-year-old man. The mass was 17 x 12 x 11 cm, smooth, round, homogeneous, and was seen in the left upper lung field. Chest computed tomography revealed a cystic mass in contact with the left lung, the chest wall, the esophagus, and the aorta. Magnetic resonance imaging showed a wall that divided the mass into two compartments. The cystic lesion was removed and was found to contain a yellow liquid. The larger part of the mass was histologically similar to esophageal wall and the smaller part was bronchogenic. The final diagnosis was mediastinal esophago-bronchogenic cyst. In previously reported cases, two cystic masses were connected by a canal. The findings in this case support the theory by Yoshii that this type of cyst originates from the diverticulum of the foregut near the lung bud.

Adult↗

PubMed1996

Pulmonary fibrosis in a carpenter with long-lasting exposure to fiberglass.

A 56-year-old male carpenter had a history of glass fiber inhalation for 41 years without any protective device. His chest radiograph showed small nodular opacities in lower lung fields and multiple cystic lesions and low attenuation areas in upper lung fields. Light and polarizing microscopic examinations of his transbronchial lung biopsy specimen revealed mild interstitial fibrosis and mononuclear cell infiltration in alveolar walls without birefringent substances. However, widespread depositions of small glass fibers (< 2.5 microns in length and 0.3 micron in diameter) were detected by analytical electron microscopy, which suggested their possible contribution to the development of his pulmonary fibrosis.

Glass↗

PubMed1996

Thallium-201 uptake, histopathological differentiation and Na-K ATPase in lung adenocarcinoma.

UNLABELLED: To clarify differences in accumulation in 201 Tl scintigraphy, we examined the relationship between uptake of 201 Tl, histopathological differentiation and Na-K ATPase. METHODS: Thallium-201 SPECT was performed twice: 15 min (early scan) and 120 min (delayed scan) after intravenous injection of 3 mCi 201 Tl-chloride. The uptake ratio of 201 Tl was calculated and compared with the grade of differentiation and the staining pattern of Na-K ATPase. RESULTS: The sensitivity of 201 Tl SPECT for well-differentiated adenocarcinomas was lower than that for moderately and poorly differentiated ones. The uptake ratio on the delayed scan was significantly lower in the well-differentiated group than that in the moderately and poorly differentiated groups. This parameter was also significantly higher in the Na-K ATPase-positive group than the -negative group. CONCLUSIONS: These results indicate that the uptake ratio of 201 Tl SPECT may be a noninvasive indicator of the grade of pathological differentiation of adenocarcinoma and provide insight into the relationship among 201 Tl SPECT, malignancy and Na-K ATPase.

Adenocarcinoma↗

PubMed1996

[Three siblings with interstitial pneumonia].

Patient 1: A 64-year-old woman was admitted for further examination after reticulonodular shadows were found on a chest X-ray film. Idiopathic interstitial pneumonia (IIP) was diagnosed. Patient 2: The 60-year-old sister of patient 1 was admitted for further examination after reticulonodular shadows were found on a chest X-ray film. IIP was diagnosed. About half a year later, her proximal interphalangeal joints had become swollen and the result of a rheumatoid hemagglutination test was positive. Therefore, the pneumonia was suspected to have been caused by a collagen-vascular disease (CVD), rheumatoid arthritis. Patient 3: The 64-year-old brother of patient 1 was examined. A chest X-ray film revealed reticulonodular shadows that were strongly suggestive of IIP. The remaining three siblings were examined. In a 62-year-old sister, the chest X-ray film was normal, but the level of anti-nuclear antigen was elevated. The fact that the level of this antigen was high in these four siblings and that the 60-year-old sister later suffered from rheumatoid arthritis suggested the presence of a factor predisposing to CVD in these siblings. The interstitial pneumonia in these siblings may have been related to CVD.

Arthritis, Rheumatoid↗

PubMed1995

[A patient with cryptogenic organizing pneumonitis who presented with multiple patchy shadows].

A 62-year-old woman was admitted to our institution for abnormal shadows on a screening chest roentgenogram. An immunoelectrophoresis test on admission revealed a polyclonal gammopathy. In her bronchoalveolar lavage fluid, the percentage of lymphocytes was found to be high: 47%. These results indicated an abnormal immunological state. A chest X-ray film showed multiple patchy shadows in both lungs. A chest CT scan revealed that the shadows were distributed peripherally, and abutted the pleura. Before treatment, the lesions enlarged toward the hilum concentrically, and cleared from the pleural side. This change is characteristic of cryptogenic organizing pneumonitis. The pathological finding at open lung biopsy was organizing pneumonitis. Bronchiolitis obliterans was not pathologically recognized. The shadows on the chest X-ray film almost completely disappeared after treatment with predonisolone at a daily dose of 30 mg. We diagnosed this as a case of cryptogenic organizing pneumonitis with typical shadows.

Female↗

PubMed1994

Tumor angiogenesis in human lung adenocarcinoma.

BACKGROUND: Hematogenous metastasis requires angiogenesis within the tumor. Previous studies have shown that microvessel counts in histologic sections of the primary tumor, which reflect angiogenesis, are correlated with metastasis in breast, prostate and Stage I nonsmall cell lung carcinoma. In this study, the authors investigated the association between angiogenesis, hematogenous metastasis and lymph node metastasis in all stages of lung adenocarcinoma. METHODS: Microvessels were highlighted by immunostaining endothelial cells for factor VIII. We counted microvessels within the tumors of 42 patients who had surgical resection (25 with relapse and 11 without relapse more than 5 years after surgical resection). Without knowledge of patient outcome, microvessels were counted on a 200x field (0.723 mm2) in the most active areas of neovascularization. RESULTS: The microvessel counts from patients with relapse after surgical resection (mean +/- standard deviation, 75.4 +/- 64.3) were significantly higher than those without relapse more than 5 years after surgical resection (42.6 +/- 26.0) (P = 0.027). Analysis of regional lymph node metastases (factor N) revealed that the microvessel counts were 62.6 +/- 35.1 for N0 (no regional lymph node metastasis), 51.7 +/- 22.2 for N1 (metastasis in ipsilateral, peribronchial and/or ipsilateral hilar lymph nodes, including direct extension), 75.4 +/- 75.3 for N2 (metastasis in ipsilateral mediastinal and/or subcarinal lymph nodes), and 74.0 for N3 (metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene or supraclavicular lymph node[s]), and these values were not significantly different from each other. CONCLUSIONS: Angiogenesis assessed by microvessel counts, correlated positively with relapse after surgical resection and hematogenous metastasis in all stages of lung adenocarcinoma; there was no correlation with lymph node metastasis in lung adenocarcinoma.

Adenocarcinoma↗

PubMed1994

Immunohistochemical study of cathepsin B. Prognostic significance in human lung cancer.

BACKGROUND: The concentration of cysteine proteinase cathepsin B has been shown to be elevated in association with malignancy or metastatic potential of human and rodent tumors, but its prognostic value for human lung cancer remains undetermined. METHODS: Using a polyclonal antibody, immunohistochemical analyses of cathepsin B were performed on paraffin embedded sections of tumors obtained surgically from 108 patients with non-small cell lung cancer (49 squamous cell carcinomas, 59 adenocarcinomas). The immunohistochemical expressions of cathepsin B in the tumors were compared with patient survival. RESULTS: Higher grade expression of cathepsin B was associated significantly with shorter survival in non-small cell lung cancer (P < 0.01), in squamous cell carcinoma (P < 0.05), and in adenocarcinoma (P < 0.01). A similar result also was seen in Stage I non-small cell lung cancer (P < 0.05). CONCLUSIONS: The authors concluded that the immunohistochemical staining pattern of cathepsin B may be a useful predictor of survival for human lung cancer.

Adenocarcinoma↗

PubMed1994

Retention index of thallium-201 single photon emission computerised tomography (SPECT) as an indicator of metastasis in adenocarcinoma of the lung.

We examined the relationship between the retention of thallium-201 (201Tl) on a delayed scan and the metastatic potential of adenocarcinomas of the lung. We studied 43 patients with adenocarcinoma of the lung and divided them into two groups according to the presence or absence of lymph node metastasis. 201Tl single photon emission computerised tomography (SPECT) was conducted twice: 15 min (early scan) and 120 min (delayed scan) after intravenous injection of 3 mCi of 201Tl chloride. We calculated the retention index in order to evaluate the degree of 201Tl retention in the primary tumour. The retention indices were significantly higher in the group that was positive for lymph node metastasis than in the negative group. In adenocarcinomas with high metastatic potential, 201Tl SPECT demonstrated slow washout or increased retention on the delayed scan. The retention index of 201Tl SPECT is a useful indicator of metastatic potential, thereby facilitating the prediction of prognosis, and provides insight into the relationship between 201Tl uptake and malignancy. This is the first report demonstrating a significant relationship between the retention of 201Tl SPECT and lymph node metastasis.

Adenocarcinoma↗